When a site has a lot of domains it's not very convenient to manage menu items for a user with the 'Administer Menu items across Domains' permission.
He can see all the menu items for all domains in any domain context and it's not very easy to browse the targeted items.
It could be a good option for the user's experience to filter the menu items list of the current domain to decrease the number of item in the list and target user's domain which is logged in.
Add tabs from the manage menu form and a filter action form the table menu overview on click on the "Current domain" tab.
Perhaps go further, providing not only "All domains" / "Current domain" tabs but a tabs for each domains that the current user is allowed to access / manage.
Active
2.0
Code
I really like the idea of having a filter for current domain.
Having a tab for all the assigned domains will have a performance issue I think and will be unmanageable when having a lot of domains.
I'm happy to review any provided MR but won't have the time myself to build it.